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Monolithic Power Systems, Inc.

MPWR
Exchange
Nasdaq
Industry
Semiconductors & Related Devices
SEC CIK
0001280452

In the last 90 days, Monolithic Power Systems, Inc. insiders filed 0 open-market purchases and 5 sales; 1,258 institutions reported holding it in 13F filings for Q2 2026, worth $65.6B in total; superinvestors D1 Capital Partners and Maverick Capital hold it.

Open-market trades, last 90 days

Open-market purchases (P) and sales (S) by Monolithic Power Systems, Inc. insiders, counted by Form 4 filing. Trades with a flagged price and duplicate filings are left out.

Open-market buys
0 filings
Open-market sells
5 filings
3 insiders, $40.5M in total
Insiders trading
3
Net value
−$40.5M
Purchases minus sales

Insider roster

Directors, officers and 10% owners who have filed a Form 4 for Monolithic Power Systems, Inc., current and former, most recent filer first. Last reported holding is the position after the last non-derivative trade in their latest filing.

Insider roster for Monolithic Power Systems, Inc.
NameTitleLast reported holdingLast filingFilings, past year
Sciammas MauriceEVP, WW Sales & Marketing49,062IndirectNov 5, 202620
Hsing MichaelCEO818,264Sep 30, 202610
Tseng SariaEVP & General Counsel2,000IndirectSep 2, 202612
Dean Robert W IIInterim CFO7,089Aug 26, 20267
Chang Kuo Wei HerbertDirector515Aug 25, 20265
Zhou JeffDirector3,800May 27, 20263
Xiao DemingEVP, Global Operations205,959May 8, 20263
Elmiger Eugen JDirector5,402May 8, 20262
Wynne EileenDirector1,007May 8, 20262
Lee Victor KDirector27,756Feb 11, 20264
Blegen TheodoreEVP and CFO82,353Feb 10, 20265
Martinez CarintiaDirector1,067Feb 5, 20261
Moyer James CDirector0IndirectAug 29, 20240

Insider trades

Each row adds up one type of transaction in one Form 4 filing. Only open-market purchases (P) and sales (S) are shown by default; use the filters to see grants, option exercises and other codes.

Insider trades
Filed (ET)Trade dateFiling delayInsiderTransactionSharesAvg priceValueHolding changeFlags
Sep 30, 2026 (view filing)5:21 PM ETSep 282 daysHsing MichaelCEOSSale−30.0K$1,344.97−$40.3M−3.5%818.3K after8 lots10b5-1
Aug 26, 2026 (view filing)7:22 PM ETAug 242 daysDean Robert W IIInterim CFOSSale−32$1,297.72−$41.5K−0.4%7.09K after
Aug 25, 2026 (view filing)7:13 PM ETAug 241 dayChang Kuo Wei HerbertDirectorSSale−50$1,281.57−$64.1K−8.8%515 after
Aug 19, 2026 (view filing)8:44 PM ETAug 172 daysDean Robert W IIInterim CFOSSale−6$1,413.64−$8.48K−0.1%7.13K after
Aug 13, 2026 (view filing)5:23 PM ETAug 112 daysChang Kuo Wei HerbertDirectorSSale−50$1,420.00−$71.0K−8.1%565 after
Aug 6, 2026 (view filing)6:20 PM ETAug 51 dayDean Robert W IIInterim CFOSSale−105$1,344.27−$141.1K−1.5%7.13K after
Aug 5, 2026 (view filing)5:33 PM ETAug 32 daysSciammas MauriceEVP, WW Sales & MarketingSSale−30$1,343.94−$40.3K−2.6%1.12K after10b5-1
Jul 17, 2026 (view filing)5:43 PM ETJul 152 daysSciammas MauriceEVP, WW Sales & MarketingSSale−15.0K$1,349.73−$20.2M−9.0%151.6K after18 lots10b5-1
Jul 6, 2026 (view filing)5:51 PM ETJul 15 daysSciammas MauriceEVP, WW Sales & MarketingSSale−30$1,351.61−$40.5K−2.5%1.15K after10b5-1
Jun 3, 2026 (view filing)Jun 12 daysSciammas MauriceEVP, WW Sales & MarketingSSale−30$1,533.95−$46.0K−2.5%1.18K after10b5-1
May 29, 2026 (view filing)May 272 daysTseng SariaEVP & General CounselSSale−7.57K$1,700.00−$12.9M−5.0%144.2K after
May 28, 2026 (view filing)May 262 daysDean Robert W IIInterim CFOSSale−22$1,649.56−$36.3K−0.4%5.88K after
May 27, 2026 (view filing)May 261 dayZhou JeffDirectorSSale−486$1,680.00−$816.5K−11.3%3.80K after
May 27, 2026 (view filing)May 225 daysTseng SariaEVP & General CounselSSale−5.00K$1,586.43−$7.93M−3.2%151.8K after
May 20, 2026 (view filing)May 182 daysHsing MichaelCEOSSale−40.0K$1,482.75−$59.3M−4.5%848.3K after13 lots
May 20, 2026 (view filing)May 182 daysDean Robert W IIInterim CFOSSale−4$1,563.28−$6.25K−0.1%5.90K after
May 19, 2026 (view filing)May 154 daysSciammas MauriceEVP, WW Sales & MarketingSSale−12.0K$1,561.40−$18.7M−6.7%166.6K after8 lots10b5-1
May 8, 2026 (view filing)May 62 daysElmiger Eugen JDirectorSSale−12.0K$1,584.96−$19.0M−69.0%5.40K after9 lots
May 8, 2026 (view filing)May 62 daysXiao DemingEVP, Global OperationsSSale−30.0K$1,654.55−$49.6M−12.7%206.0K after4 lots
May 8, 2026 (view filing)May 62 daysWynne EileenDirectorSSale−335$1,582.68−$530.2K−25.0%1.01K after
May 6, 2026 (view filing)May 5-61 dayZhou JeffDirectorSSale−1.51K$1,607.85−$2.43M−26.1%4.29K after3 lots
May 6, 2026 (view filing)May 51 daySciammas MauriceEVP, WW Sales & MarketingSSale−380$1,583.81−$601.8K−29.3%919 after
May 6, 2026 (view filing)May 42 daysSciammas MauriceEVP, WW Sales & MarketingSSale−30$1,588.73−$47.7K−2.4%1.21K after10b5-1
Apr 10, 2026 (view filing)Apr 82 daysTseng SariaEVP & General CounselSSale−8.96K$1,305.22−$11.7M−5.4%157.0K after10 lots10b5-1
Apr 8, 2026 (view filing)Apr 62 daysTseng SariaEVP & General CounselSSale−7.64K$1,167.95−$8.92M−4.4%165.9K after8 lots10b5-1
Apr 3, 2026 (view filing)Apr 12 daysTseng SariaEVP & General CounselSSale−1.40K$1,133.52−$1.59M−0.8%173.6K after5 lots10b5-1
Apr 3, 2026 (view filing)Apr 12 daysSciammas MauriceEVP, WW Sales & MarketingSSale−30$1,116.44−$33.5K−2.4%1.24K after10b5-1
Apr 1, 2026 (view filing)Mar 302 daysTseng SariaEVP & General CounselSSale−25.7K$1,010.50−$25.9M−12.8%175.0K after8 lots10b5-1
Mar 24, 2026 (view filing)Mar 204 daysSciammas MauriceEVP, WW Sales & MarketingSSale−30$1,095.07−$32.9K−2.3%1.27K after10b5-1
Feb 17, 2026 (view filing)Feb 125 daysHsing MichaelCEOSSale−33.0K$1,171.83−$38.7M−3.6%888.2K after12 lots10b5-1
Feb 13, 2026 (view filing)Feb 112 daysHsing MichaelCEOSSale−33.0K$1,188.92−$39.2M−3.5%921.2K after10 lots10b5-1
Feb 12, 2026 (view filing)Feb 111 daySciammas MauriceEVP, WW Sales & MarketingSSale−200$1,179.98−$236.0K−13.3%1.30K after
Feb 12, 2026 (view filing)Feb 102 daysHsing MichaelCEOSSale−34.0K$1,142.28−$38.8M−3.4%954.2K after9 lots10b5-1
Feb 11, 2026 (view filing)Feb 92 daysLee Victor KDirectorSSale−400$1,212.16−$484.9K−1.4%27.8K after10b5-1
Feb 10, 2026 (view filing)Feb 64 daysXiao DemingEVP, Global OperationsSSale−22.9K$1,171.16−$26.8M−8.8%235.9K after
Feb 10, 2026 (view filing)Feb 64 daysTseng SariaEVP & General CounselSSale−22.9K$1,171.16−$26.8M−10.2%200.6K after
Feb 10, 2026 (view filing)Feb 64 daysSciammas MauriceEVP, WW Sales & MarketingSSale−22.9K$1,171.16−$26.8M−11.4%178.6K after
Feb 10, 2026 (view filing)Feb 64 daysBlegen TheodoreEVP and CFOSSale−21.7K$1,171.16−$25.4M−20.9%82.4K after
Feb 10, 2026 (view filing)Feb 64 daysHsing MichaelCEOSSale−54.9K$1,171.16−$64.3M−5.3%988.2K after
Feb 4, 2026 (view filing)Feb 22 daysBlegen TheodoreEVP and CFOSSale−3.00K$1,129.76−$3.39M−4.4%65.3K after17 lots10b5-1
Jan 6, 2026 (view filing)Jan 24 daysLee Victor KDirectorSSale−600$930.86−$558.5K−2.1%28.0K after10b5-1
Jan 6, 2026 (view filing)Jan 24 daysBlegen TheodoreEVP and CFOSSale−3.00K$940.47−$2.82M−4.2%68.3K after15 lots10b5-1
Dec 29, 2025 (view filing)Dec 245 daysLee Victor KDirectorSSale−1.00K$951.72−$951.7K−3.4%28.6K after6 lots10b5-1
Dec 2, 2025 (view filing)Dec 11 dayBlegen TheodoreEVP and CFOSSale−3.00K$908.21−$2.72M−4.0%71.3K after10 lots10b5-1
Nov 28, 2025 (view filing)Nov 262 daysTseng SariaEVP & General CounselSSale−20.0K$926.47−$18.5M−10.7%167.3K after9 lots
Nov 28, 2025 (view filing)Nov 253 daysTseng SariaEVP & General CounselSSale−20.0K$904.18−$18.1M−9.6%187.3K after19 lots
Nov 25, 2025 (view filing)Nov 25Same dayChang Kuo Wei HerbertDirectorSSale−100$896.97−$89.7K−19.0%426 after
Nov 25, 2025 (view filing)Nov 241 daySciammas MauriceEVP, WW Sales & MarketingSSale−3.98K$895.23−$3.56M−2.7%144.3K after
Nov 24, 2025 (view filing)Nov 213 daysChang Kuo Wei HerbertDirectorSSale−100$873.97−$87.4K−16.0%526 after
Nov 20, 2025 (view filing)Nov 191 daySciammas MauriceEVP, WW Sales & MarketingSSale−28.0K$881.66−$24.7M−15.9%148.3K after12 lots